Magnetic cross valve having selfstarting characteristics



Sept. 16, 1952 H. J. MQCREARY 2,611,120

MAGNEITiIC CROSS VALVE HAVING SELF-STARTING CHARACTERISTICS OriginalFiled June 21, 1950 FIG. I

OUTPUT 2o CY.

INPUT 130v so CY.

OUTPUT 20 cm INPUT 130v eo'cx OUTPUT 2o CY.

INPUT. 130v. so on IN V EN TOR. HAROLD J. M CREARY ATTORNEY PatentedSept. 16, 1952 MAGNETIC CROSS VALVE HAVING SELF- STARTINGCHARACTERISTICS Harold J. McCreary, Lombard, Ill., assignor to AutomaticElectric Laboratories, Inc., Chicago, 111., a corporation of DelawareOriginal application June 21, 1950, Serial No. 169,489. Divided and thisapplication January 17, 1951, Serial No. 206,377

4 Claims. (Cl. 32168) This invention relates in general to frequencychangers, and more particularly to a means for deriving current of onefrequency from a source of current of a different frequency.

An object of the present invention is to provide a sub-frequencygenerator of the magnetic cross valve type having saturating windingscoupled to the primary Winding for providing a biasing flux.

Another object of the present invention is to provide a sub-frequencygenerator of the magnetic cross valve type having self -startingcharacteristics wherein circuit means coupled to the input currentsource provide a direct current biasing flux. 7

Another object of the present invention is to provide a sub-frequencygenerator of the magnetic cross valve type having a permanent magnetproviding biasing flux in order to provide self-startingcharacteristics.

Other objects of the invention will appear upon a further perusal of thespecification taken in conjunction with the accompanying drawings whichillustrate several of the embodiments of the invention in the form ofschematic diagrams.

Fig. 1 is a diagrammatic representation of a magnetic cross valvesub-frequency generator using permanent magnets to provide a biasingflux at the center of the magnetic cross valve core.

Fig. 2 is a diagrammatic representation of a magnetic cross valvesub-frequency generator in which the leg coils produce a biasing flux byrectifying the input signal.

Fig. 3 is a diagrammatic representation of'a magnetic cross valvesub-frequency generator having a biasing flux produced by using lowvoltage rectifiers to rectify current flow through a winding coupled tothe primary winding.

This application is a divisional application of now pending applicationfor Magnetic Frequency Divider, filed June 21, 1950, Serial No. 169,489.

In the magnetic cross valve systems of the type herein used two windingsare displaced by 90 degrees so as to provide that the mutual inductancebetween the respective windings is substantially zero at partialsaturation, but which induces odd harmonics in the secondary winding athigh degrees of saturation.

In the present invention, additional saturating windings arewound aroundthe legs of the cross valve to provide D. C. flux to bias the crossvalve to a point close to saturation and thereby provide a self-startingsystem. The additional saturating windings are coupled to the inputcurrent source.

In addition thereto, a cross coil is provided to provide a differentialflux. The frequency of the cross coil added to the frequency of thesecondary winding will equal the input signal. The oscillating frequencyof the cross coil is caused by a flux diiferential between the D. C.saturating flux and the flux produced by the input signal. Theoscillating frequency for the output winding is provided by'thesaturating flux and the flux provided by the oscillation of the crosscoil. 'In one embodiment, a permanent magnet used to provide thesaturating flux and the cross coil will provide an alternating currentto produce an alternating flux, which is superimposed on the D. C. fluxproduced by the permanent magnet,

Referring now to Fig. 1, a cross valve I0 herein provided may be of thetype shown in Patent No. 2,455,078 issued on November 30, 19918, to thepresent inventor, Patent No. 2,461,992, issued on February 15, 1949, tothe present inventor, and Patent No. 2,455,857, issued on July 27, 1948,to the present inventor. The cross valve has two intersecting members.An air gap is shown'at two points alternately opposite the horizontalintersecting member. Permanent magnet H is shown extending from thehorizontal intersecting member to the top of the cross valve. Anotherpermanent magnet 12 is shown extending from the other end of thehorizontal intersecting member to the bottom of the cross valve II]. Theprimary winding I3 is wound through opposite dia gonal corners of theintersecting members. Serially connected to the primary winding I3 aretwo additional windings I4 and I5. Winding I4 is wound around oneintersecting member and winding I5 is wound around the otherintersecting member. The power supply providing 130 volts at cyclesenergizes the primary winding I3 and the two additional windings I4 andI5. Cross winding I 6 is wound through the other diagonal corners of theintersection of the cross valve In. The cross winding I6 is displaceddegrees from the primary windin I 3. Condenser I1 is connected to thecross winding Hi to provide a resonant circuit. The output circuitcomprises two secondary windings I8 and I9 and the condenser 20. Thewinding I8 is wound around the same intersecting member as is theadditional winding I 4, but at an opposite point. The secondary windingI9 is wound around the same intersecting member as is additional windingI5, but at an opposite point. The output circuit comprising condenser 20and secondary windings I8 .and I9 is tuned to the output frequency at 20cycles. In more detail, a volt 60 cycle power supply energizes theadditional windings I4 and I5 and the primary winding I3. The permanentmagnets H and I2 produce all C. saturating flux in the core of the crossvalve i ii. The differential flux produced by the D. C, saturating fluxand the alternatingfiux produced by the primary winding l3 inducesavoltage in the resonating cir=- cuit comprisin the cross coil and thecondenser H. The circuit including cross coil l6 and the condenser I? istuned to 40 cycles. Itis to be noted that there is no mutualinductancebetween the coil 16 and the coil i3, until the mag netic coreIii has reached a pointofnearsaturation which is produced by the D. C.magnetizing flux.

A voltage is now produced in the secondary windings I8 and IQ ofthe-output circuit. The

induced voltage is producedby a fiux differential caused by the D. C'.saturating flux produced by the permanent magnets H and i2 and thealternating flux produced by the winding 26. As a result thereof. a..20.cycle voltage is induced in the windingsl8 and I9, since a resonatingcircuit comprising. theserespective windings and the condenser 2li-istunedfor. that frequency. The 20 cycleirequency of theoutputwinding plusthe -40, -cycle.frequency of the cross winding equals ,the 60. cycleinput frequency of th'eprimary winding.

Referringnow to Fig. 2,,a cross valve 2| herein usedmay be. of the typedisclosed in the previously mentioned patents. The crossvalve has twointersecting members forming two pair of diagonally opposite corners. Aprimary winding .22 is. wound diagonally through. two corners. of

. ing inductance coil 28, condenser 29, and rectifier 30. A crosswinding Si is wound around the other diagonal corners of theintersection of the cross valve 2!. Condenser 32 is connected to thecross winding, to provide a resonating circuit. The output circuitcomprises condenser 33 and secondary windings 34 and 35. Secondarywinding 34 is wound around the same intersecting member asis'auxiliary'winding 24, but at an opposite end. Secondary winding 35 iswound around the same intersecting member as is auxiliary winding 23,but at an opposite end. The-condenser 33 provides' a resonating circuitwith the secondary windings 34 and 35 to oscillate at 20 cycles. In moredetail, the 130 volt 60 cycle power supply energizes the primary winding'22 and the auxiliary windings 23 and 24 over the following path: powersupply, auxiliary winding 23, primary winding 22, auxiliary winding 24and back to the power supply. A direct current is produced inithe-auxiliary winding 23 by the rectifying circuit over "the followingpath: rectifier 27, auxiliary winding '23, inductancecoil 25 and backtothe rectifier 21. In a similar manner direct current is -produced in'theauxiliary winding '24 over the following path: rectifier 30, inductance'coil' 28, auxiliary winding'24 and backto the rectifier 30. Coil 22 isso wound as to have twice thenumber of turnsof either'coil 23 or coil24. Additional fiux, over and above the flux produced in theintersecting 'members by the leg coils 23 and 24. is

produced in'the intersecting members by coil 22.

This-"additional. fiuxdncluces voltages in the leg coils 23 and '24, andthe additional current in leg coils 23 and 24 has a low impedance paththrough the aforementioned rectifying circuits. The rectified current inthe auxiliary coils 23 and 24 produces D.C. magnetizing .fiuxes' whichare opposing-one another. As'a result thereof, voltage is induced in thecross winding 3| by a differential "fiux produced by the 'fiux of theprimary winding ofthe-coil 22 and the D. C. saturating flux produced bythe auxiliary windings 23 and 24. The circuit comprising the cross coil3i and condenser 32 oscillates at 40 cycles.

.A voltage is now induced in the secondary windings 34 and 35 which iscaused by a differentialiiux Thisdifierential fiux is produced by the D.C. saturatingflux provided by the auxiliary windingsZii and '24 andalternating fiux provided bythecross winding 3 l. The output circuit,comprising secondary windings 34 and 35 and condenser 33, oscillates atthe tuned frequency 2!) cycles; 7/

Referring now to Fig. 3 which is a schematic diagram showing'how a D. C.field can'be produced using a low voltage rectifier on the leg coils.Cross valve 56 herein used may be of the type disclosed in saidpreviously mentionedpatents. The cross valvehas two intersecting membersforming two pairof opposite diagonal corners. An input winding 31 iswound through a pairof the opposite diagonal corners at theintersection. serially connected to the primary winding 31 are twoauxiliary windings 3B and 39. Auxiliary winding 38 is wound around oneof the intersecting members, while winding 39 is wound around the otherintersecting member. saturating winding 40 is wound on the sameintersecting member as is wound auxiliary winding 38. In a similarmanner, the saturating winding M is wound around the same intersectingmember 'as is wound the auxiliary winding 39. Additional winding 42 iswound through the same diagonal corners as is wound the primary winding31. The primary winding 31 and the additional winding 42 aremagnetically coupled. A circuit comprising'rectifiers 43, 44, 45, 46 andcondenser dlconnects the saturating windings ell and 4! with theadditionalwinding 42. The cross winding'48 is wound through the otheropposite diagonal corners of thelntersection and'is displaced degreesfrom the primary winding '31. A condenser 49 forms an oscillatingcircuit with the-cross winding 48 to oscillate at 40' cycles. The outputcircuit comprises. secondary windings 50 and 5! and the condenser 52 andis tunedto 20 cycles. The secondary winding bli is wound aroundthe sameintersecting member as is auxiliary winding 39, but at an oppositepoint. The secondary winding 5! is wound aroundthe same intersectingmember. as is auxiliary winding'38, but. at an opposite point. In moredetail, the power supply providing volts at 60 cyclesenergizestheauxiliary windings 38 and 39 and the primary winding 3?. Theadditional winding 42 is magnetical- 1y. coupled to the primary windingS'l'and thereby a voltageis inducedin the additional winding. As aresult thereof, a rectified voltage is produced in the saturatingwindings 4i] and 4| over the following path: additional winding 42,rectifier 4E5, saturating winding 40, saturating-winding 4|, rectifier44" and back to the additional winding 42. The saturating windings'40and'4l produce a D. C. saturating flux for the cross. valve 36, therebyproviding a biasingfiux. Voltage-is induced in thecrosstwinding 48.. bya difierential fiux'p'roduced by the D. C. saturating flux and analternating flux. The D. C. saturating flux which is a biasing flux isproduced by the windings 4a and 4|. The alternating current flux isproduced by the windings 39, 38 and 3!. Since the cross winding 48 istuned to 40 cycles by the con.- denser 49, that circuit will oscillateat the desired frequency. As a result thereof, voltage is induced in thesecondary windings 59 and 5| which is caused by a difierential flux. Thedifferential flux is produced by the D. C. magnetizing flux and thealternating current flow. The last mentioned D. C. saturating flux isprovided by the saturating windings 45] and 4! and the alternatingcurrent flux is produced by the cross winding 48. the secondary windings50 and 5t, to oscillate at 20 cycles, the output frequency derived fromthis system is a 20 cycle signal.

Although I have described my invention with a certain degree ofparticularlity it should be understood that the present disclosure hasbeen made only by way of example and that numerous changes in thedetails of construction and the completion and arrangement of parts maybe resorted to without departing from the true spirit Since thecondenser 52 is tuned with and scope of the invention as hereinafterclaimed.

What is claimed is: 1. In a static frequency changer, a saturablemagnetic core having a pair of intersecting mem hers, a primary windingwound through one pair of diagonally opposite corners of theintersection, a secondary circuit including a condenser and a coil woundaround said pair of intersecting members, a source of alternatingcurrent con nected to said primary winding for providing the inputsignal, said input signal producing an input flux in said core, a loadcircuit connected to said secondary circuit, a permanent magnet disposedabout said magnetic core for providing a biasing flux in said core, anda cross winding wound through the other pair of diagonally oppositecorners of said intersection, a condenser connected across said crosswinding forming a resonant circuit, said resonant circuit resonatingresponsive to said input flux and said biasing flux to produce adifferential flux in said core, whereby alternating currents having afrequency integrally related to the frequency of said source isdelivered to said load circuit.

2. In a frequency changer, a magnetic core structure having twointersecting members, a primary circuit including a coil wound through apair of diagonal corners of the intersection, a source of alternatingcurrent for energizing said primary circuit to provide the input signal,a secondary circuit including a condenser and a coil wound around thetwo intersecting members and tuned to the desired output frequency, apair of permanent magnets disposed at diagonally opposite positions ofsaid magnetic core structure to provide a biasing flux in said magneticcore structure, a differential circuit tuned to an intermediatefrequency and having a condenser and a coil wound through the other pairof diagonal currents to provide continuous oscillating current inresponse to the flux differential produced by the 6 biasing flux of saidpermanent magnets and the differential flux of said primary circuit,said secondary circuit oscillates to the tuned frequency in response tothe flux differential set up by said differential circuit and thebiasing flux of said permanent magnets, thereby providing selfstartingcharacteristics.

3. In a frequency changer, a magnetic core structure having twointersecting members, a primary circuit including a coil wound through apair of opposite diagonal corners of the intersection, a source ofalternating current of a certain frequency for energizing said primarycircuit to provide an input signal, said input signal producing an inputflux in said core, a pair of permanent magnets disposed about saidmagnetic core structure to provide a biasing flux for said magnetic corestructure, and an output winding having a load circuit connected theretoand wound through the other pair of diagonal corners of saidintersection, said output winding having a condenser connectedthereacross, thereby forming a circuit resonant to a certain outputfrequency, another resonant circuit comprising a condenser and a coilwound about the other pair of opposite diagonal corners of theintersection and resonant at a frequency which is the dinerence betweenthe aforementioned frequencies, said last mentioned circuit resonatingresponsive to the input flux and the biasing flux for producing adifferentiai fiux in said core, whereby a1 ternating currents areproduced in said load circuit in response to the biasing flux producedby said permanent magnets and the differential flux produced by saidprimary winding, thereby providing self-starting characteristics.

4. In a frequency changer, a magnetic core structure having twointersecting members, a primary winding wound through a pair of oppositediagonal corners of the intersection, a source of alternating current ofa certain frequency for energizing said primary winding to provide aninput signal, said input signal inducing input fluxes of odd harmonicsof said input signal frequency in said core when said core is saturatedby a biasing flux, an output winding wound around said intersectingmembers, a condenser connected across said output winding forming acircuit resonant at a sub-harmonic frequency of said input signal, aload circuit connected to said secondary Winding, resonating meansassociated with said core for producing a differential fiux in said coreof a frequency which is the difference between said input frequency andsaid subharmonic frequency, and a pair of permanent magnets disposedabout said magnetic core for providing a biasing flux in said magneticcore, whereby alternating currents of said subharmonic frequency areproduced in said load circuit, thereby providing self-startingcharacteristics.

HAROLD J. MCCREARY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

